1. Field of the Invention
The present invention relates to an optical disc data recording and reproducing apparatus which optically reads data from or writes data onto an optical disc. More precisely, it relates to a driving apparatus which electromagnetically drives an objective lens thereof.
2. Description of Related Art
In a known optical disc apparatus, such as an opto-magnetic disc apparatus, an objective lens is held on a carriage which is movable in a radial direction (i.e., tracking direction) of the optical disc. The objective lens is movable, through an elastic member, in the tracking direction and the focusing direction. Tracking and focusing coils are provided on an objective lens holder. An electromagnetic driving circuit made up of a magnetic circuit and the tracking and focusing coils is provided to drive the objective lens in the tracking direction and in the focusing direction. The focusing and tracking coils are supplied with predetermined directions and intensities of electric current to drive the objective lens holder, so that the laser beams can be accurately converged onto the recording track of the optical disc by the objective lens.
In such a known electromagnetic objective lens driving apparatus, the carriage is moved in the radial direction of the optical disc to move the objective lens holder on the carriage. It is necessary to make the carriage and the lens holder as light as possible for fast track access and precise focusing and tracking operations. For instance, in a support mechanism in which the objective lens holder is supported through suspension wires, the lens holder is heavy and unable to accelerate quickly.